GB2194480A - Exothermic cutting rods - Google Patents

Abstract

An exothermic cutting rod includes a case (3) of ferrous metal with an inner and an outer corrosion resistant coating (2), the outer coating (2) being overlaid by an insulating coating (1), exothermic fuel means within the case (3) being in the form of a plurality of wires of which some at least are in the form of a tube (4) containing a powder mix (5) essentially of ferrous material but including small quantities of aluminium and manganese. <IMAGE>

Description

SPECIFICATION Exothermic cutting rods The invention concerns exothermic cutting rods.

According to the present invention there is proposed an exothermic cutting rod including a tubular rod case of a ferrous material, an electrically insulating coating at the outer surface of the said case. and exothermic fuel means provided inwardly of the said case and extending in the axial direction thereof, the said fuel means comprising a plurality of wires arranged in side-by-side disposition circumferentially of the case, some at least of the said wires being constituted by a respective ferrous tube containing a powder mix essentially of a ferrous material but including small proportions by weight of aluminium and of manganese.

According to a preferred feature, all of the wires are of like form and contain a like powder mix.

According to a further preferred feature the powder mix includes approximately 10% to 20% by weight of aluminium.

According to a still further preferred feature, at least the inner surface of the said case carries a corrosion resistant coating.

The invention will now be described further, by way of example only, with reference to the accompanying diagrammatic drawing illustrating one embodiment thereof in transverse cross-section.

Referring now to the drawing, an exothermic cutting rod comprises a tubular body or case 3 of a ferrious metal having a corrosion resistant coating 2 applied to the inner and outer surfaces thereof. An electrically insulating coating 1 is provided outwardly of the case 3.

An exothermal fuel means is provided within the case, such means being defined by a plurality of wires arranged circumferentially of the case and in side-by-side disposition therein.

Each wire comprises a ferrous tube 4 filled with a powder mix 5, the tube 4 conveniently being formed from sheet material as by rolling and the mix being essentially ferrous in character but including between 10% and 20% by weight, of aluminium. In a typical arrangement the mix includes approximately 14% by weight of aluminium together with small quantities, by weight, of other materials.

In the ordinary course of events the wires will be of like form and make-up, although advantage may stem from the utilisation of a combination of wires of different characters.

Furthermore, although the wires will be essentially straight, it may be found conve nient in some instances for such wires to be of helical form.

By using a powder mix disposed within a sleeve we are able to provide a fuel means best fitted to the use circumstances involved and, furthermore, are better able to create and maintain a greater uniformity of product than is thought likely with a solid alloy rod.

1. An exothermic cutting rod including a tubular rod case of a ferrous material, an electrically insulating coating at the outer surface of the said case, and exothermic fuel means provided inwardly of the said case and extending in the axial direction thereof, the said fuel means comprising a plurality of wires arranged in side-by-side disposition circumferentially of the case, some at least of the said wires being constituted by a respective ferrous tube containing a powder mix, essentially of a ferrous material but including small proportions by weight of aluminium and of manganese.

2. A cutting rod as claimed in claim 1 wherein all of the wires are of like form and contain a like powder mix.

3. A cutting rod as claimed in claim 1 or 2 wherein the powder mix includes approximately 10% to 20% by weight of aluminium.

4. A cutting rod as claimed in claim 1, 2 or 3 wherein at least the inner surface of the said case carries a corrosion resistant coating.

5. A cutting rod as claimed in claim 3 wherein the amount of aluminium is about 14%.

6. A cutting rod as claimed in any preceding claim wherein the wires are essentially straight.

7. A cutting rod as claimed in any of claims 1 to 5 wherein the wires are of helical form.

8. A cutting rod substantially as hereinbefore described with reference to the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (8)

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Exothermic cutting rods The invention concerns exothermic cutting rods. According to the present invention there is proposed an exothermic cutting rod including a tubular rod case of a ferrous material, an electrically insulating coating at the outer surface of the said case. and exothermic fuel means provided inwardly of the said case and extending in the axial direction thereof, the said fuel means comprising a plurality of wires arranged in side-by-side disposition circumferentially of the case, some at least of the said wires being constituted by a respective ferrous tube containing a powder mix essentially of a ferrous material but including small proportions by weight of aluminium and of manganese. According to a preferred feature, all of the wires are of like form and contain a like powder mix. According to a further preferred feature the powder mix includes approximately 10% to 20% by weight of aluminium. According to a still further preferred feature, at least the inner surface of the said case carries a corrosion resistant coating. The invention will now be described further, by way of example only, with reference to the accompanying diagrammatic drawing illustrating one embodiment thereof in transverse cross-section. Referring now to the drawing, an exothermic cutting rod comprises a tubular body or case 3 of a ferrious metal having a corrosion resistant coating 2 applied to the inner and outer surfaces thereof. An electrically insulating coating 1 is provided outwardly of the case 3. An exothermal fuel means is provided within the case, such means being defined by a plurality of wires arranged circumferentially of the case and in side-by-side disposition therein. Each wire comprises a ferrous tube 4 filled with a powder mix 5, the tube 4 conveniently being formed from sheet material as by rolling and the mix being essentially ferrous in character but including between 10% and 20% by weight, of aluminium. In a typical arrangement the mix includes approximately 14% by weight of aluminium together with small quantities, by weight, of other materials. In the ordinary course of events the wires will be of like form and make-up, although advantage may stem from the utilisation of a combination of wires of different characters. Furthermore, although the wires will be essentially straight, it may be found conve nient in some instances for such wires to be of helical form. By using a powder mix disposed within a sleeve we are able to provide a fuel means best fitted to the use circumstances involved and, furthermore, are better able to create and maintain a greater uniformity of product than is thought likely with a solid alloy rod. CLAIMS

1. An exothermic cutting rod including a tubular rod case of a ferrous material, an electrically insulating coating at the outer surface of the said case, and exothermic fuel means provided inwardly of the said case and extending in the axial direction thereof, the said fuel means comprising a plurality of wires arranged in side-by-side disposition circumferentially of the case, some at least of the said wires being constituted by a respective ferrous tube containing a powder mix, essentially of a ferrous material but including small proportions by weight of aluminium and of manganese.

2. A cutting rod as claimed in claim 1 wherein all of the wires are of like form and contain a like powder mix.

3. A cutting rod as claimed in claim 1 or 2 wherein the powder mix includes approximately 10% to 20% by weight of aluminium.

4. A cutting rod as claimed in claim 1, 2 or 3 wherein at least the inner surface of the said case carries a corrosion resistant coating.

5. A cutting rod as claimed in claim 3 wherein the amount of aluminium is about 14%.

6. A cutting rod as claimed in any preceding claim wherein the wires are essentially straight.

7. A cutting rod as claimed in any of claims 1 to 5 wherein the wires are of helical form.

8. A cutting rod substantially as hereinbefore described with reference to the accompanying drawings.